diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/mips/sibyte/sb1250/time.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/mips/sibyte/sb1250/time.c')
-rw-r--r-- | arch/mips/sibyte/sb1250/time.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/arch/mips/sibyte/sb1250/time.c b/arch/mips/sibyte/sb1250/time.c new file mode 100644 index 000000000000..8b4c848c907b --- /dev/null +++ b/arch/mips/sibyte/sb1250/time.c | |||
@@ -0,0 +1,136 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2000, 2001 Broadcom Corporation | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or | ||
5 | * modify it under the terms of the GNU General Public License | ||
6 | * as published by the Free Software Foundation; either version 2 | ||
7 | * of the License, or (at your option) any later version. | ||
8 | * | ||
9 | * This program is distributed in the hope that it will be useful, | ||
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
12 | * GNU General Public License for more details. | ||
13 | * | ||
14 | * You should have received a copy of the GNU General Public License | ||
15 | * along with this program; if not, write to the Free Software | ||
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | ||
17 | */ | ||
18 | |||
19 | /* | ||
20 | * These are routines to set up and handle interrupts from the | ||
21 | * sb1250 general purpose timer 0. We're using the timer as a | ||
22 | * system clock, so we set it up to run at 100 Hz. On every | ||
23 | * interrupt, we update our idea of what the time of day is, | ||
24 | * then call do_timer() in the architecture-independent kernel | ||
25 | * code to do general bookkeeping (e.g. update jiffies, run | ||
26 | * bottom halves, etc.) | ||
27 | */ | ||
28 | #include <linux/config.h> | ||
29 | #include <linux/interrupt.h> | ||
30 | #include <linux/sched.h> | ||
31 | #include <linux/spinlock.h> | ||
32 | #include <linux/kernel_stat.h> | ||
33 | |||
34 | #include <asm/irq.h> | ||
35 | #include <asm/ptrace.h> | ||
36 | #include <asm/addrspace.h> | ||
37 | #include <asm/time.h> | ||
38 | #include <asm/io.h> | ||
39 | |||
40 | #include <asm/sibyte/sb1250.h> | ||
41 | #include <asm/sibyte/sb1250_regs.h> | ||
42 | #include <asm/sibyte/sb1250_int.h> | ||
43 | #include <asm/sibyte/sb1250_scd.h> | ||
44 | |||
45 | |||
46 | #define IMR_IP2_VAL K_INT_MAP_I0 | ||
47 | #define IMR_IP3_VAL K_INT_MAP_I1 | ||
48 | #define IMR_IP4_VAL K_INT_MAP_I2 | ||
49 | |||
50 | extern int sb1250_steal_irq(int irq); | ||
51 | |||
52 | void sb1250_time_init(void) | ||
53 | { | ||
54 | int cpu = smp_processor_id(); | ||
55 | int irq = K_INT_TIMER_0+cpu; | ||
56 | |||
57 | /* Only have 4 general purpose timers */ | ||
58 | if (cpu > 3) { | ||
59 | BUG(); | ||
60 | } | ||
61 | |||
62 | if (!cpu) { | ||
63 | /* Use our own gettimeoffset() routine */ | ||
64 | do_gettimeoffset = sb1250_gettimeoffset; | ||
65 | } | ||
66 | |||
67 | sb1250_mask_irq(cpu, irq); | ||
68 | |||
69 | /* Map the timer interrupt to ip[4] of this cpu */ | ||
70 | bus_writeq(IMR_IP4_VAL, | ||
71 | IOADDR(A_IMR_REGISTER(cpu, R_IMR_INTERRUPT_MAP_BASE) + | ||
72 | (irq << 3))); | ||
73 | |||
74 | /* the general purpose timer ticks at 1 Mhz independent if the rest of the system */ | ||
75 | /* Disable the timer and set up the count */ | ||
76 | bus_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG))); | ||
77 | #ifdef CONFIG_SIMULATION | ||
78 | bus_writeq(50000 / HZ, | ||
79 | IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT))); | ||
80 | #else | ||
81 | bus_writeq(1000000/HZ, | ||
82 | IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT))); | ||
83 | #endif | ||
84 | |||
85 | /* Set the timer running */ | ||
86 | bus_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, | ||
87 | IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG))); | ||
88 | |||
89 | sb1250_unmask_irq(cpu, irq); | ||
90 | sb1250_steal_irq(irq); | ||
91 | /* | ||
92 | * This interrupt is "special" in that it doesn't use the request_irq | ||
93 | * way to hook the irq line. The timer interrupt is initialized early | ||
94 | * enough to make this a major pain, and it's also firing enough to | ||
95 | * warrant a bit of special case code. sb1250_timer_interrupt is | ||
96 | * called directly from irq_handler.S when IP[4] is set during an | ||
97 | * interrupt | ||
98 | */ | ||
99 | } | ||
100 | |||
101 | void sb1250_timer_interrupt(struct pt_regs *regs) | ||
102 | { | ||
103 | extern asmlinkage void ll_local_timer_interrupt(int irq, struct pt_regs *regs); | ||
104 | int cpu = smp_processor_id(); | ||
105 | int irq = K_INT_TIMER_0 + cpu; | ||
106 | |||
107 | /* Reset the timer */ | ||
108 | __bus_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, | ||
109 | IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG))); | ||
110 | |||
111 | /* | ||
112 | * CPU 0 handles the global timer interrupt job | ||
113 | */ | ||
114 | if (cpu == 0) { | ||
115 | ll_timer_interrupt(irq, regs); | ||
116 | } | ||
117 | |||
118 | /* | ||
119 | * every CPU should do profiling and process accouting | ||
120 | */ | ||
121 | ll_local_timer_interrupt(irq, regs); | ||
122 | } | ||
123 | |||
124 | /* | ||
125 | * We use our own do_gettimeoffset() instead of the generic one, | ||
126 | * because the generic one does not work for SMP case. | ||
127 | * In addition, since we use general timer 0 for system time, | ||
128 | * we can get accurate intra-jiffy offset without calibration. | ||
129 | */ | ||
130 | unsigned long sb1250_gettimeoffset(void) | ||
131 | { | ||
132 | unsigned long count = | ||
133 | bus_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT))); | ||
134 | |||
135 | return 1000000/HZ - count; | ||
136 | } | ||